ABSTRACT
The paper surveys what is known of the main stages of Britain's climatic history over the 10,000–15,000 years since the ice age. Evidence is given of material changes during the last 1,000 years, which are believed to have included one of the warmest and one of the coldest epochs of post-glacial time, though neither lasted more than two to four centuries.
Numerical estimates of the magnitude of these climatic differences, and of the rapidity of change, are given so far as possible. These are important if such studies of Britain's experience in the past are to yield useful guidance for the future.
From about 1890 to the 1930s Britain, in common with most of the rest of the world, experienced a remarkable warming of the climate, which affected the length and dependability of the growing season and was accompanied by changes in the prevailing winds and amount and seasonal distribution of precipitation. These trends seem generally to have reversed since 1940 or somewhat earlier. Tables of climatic statistics based on observations made in certain recent decades should therefore be used with caution. No climatic table is of much value unless the years that it comprises are specified.
There is an obvious economic call for forecasts of the climatic tendency over the decades ahead. This need cannot be met until a scientific basis for such forecasts has been created. This depends on identification and fuller (quantitative) knowledge and understanding of the physical influences and atmospheric processes that determine climatic changes. Effects, whether accidental or intended, of man's activity have to be included here. These, as well as some natural events such as the erratic output of large quantities of volcanic dust into the high atmosphere, introduce unpredictable elements into the problem.
For a long while to come, therefore, the most relevant guidance to the future must be the fullest and most specific possible knowledge of past climatic behaviour.
